Damage of Concrete and Reinforcement of Reinforced-Concrete Foundations Caused by Environmental Effects

Basic Chemical Tests of Concrete during the Assessment of Structure Suitability—Discussion on Selected Industrial Structures

“…Very simplified divisions group factors threatening RC structure durability into mechanical, atmospheric, biological, and chemical ones [7]. In practice, it is sometimes hard to distinguish between separate risk factors because their effects are often strongly interrelated (e.g., chemical aggression causes steel corrosion; then, swelling corrosion products burst concrete, which is a mechanical action).…”

“…Still, chemical agents form the most significant group of impact factors causing corrosion of concrete and reinforcement. Some of them are present in the atmosphere-an example is carbon dioxide which causes carbonation in concrete [7,11]. Other typical corrosion factors are sulfur compounds, which form gypsum in concrete (through the reaction of sulfate ions with portlandite) and, in the subsequent phase, ettringite which can be, or not, expansive.…”

“…Other typical corrosion factors are sulfur compounds, which form gypsum in concrete (through the reaction of sulfate ions with portlandite) and, in the subsequent phase, ettringite which can be, or not, expansive. Sulfur compounds are present, among other things, in the so-called industrial atmosphere and in a part of groundwater [7,12]. The abovementioned biological corrosion is also a source of concrete contamination with sulfur compounds.…”

“…Due to the nature of the paper, a chemical description of corrosive processes is not included herein because the content and aim of the paper are different. Such descriptions can be found in a number of references [7,[19][20][21].…”

“…Concrete-Specification, performance, production and conformity [36], the maximal content of chloride ions (Cl − ) in concrete in relation to the cement mass (including type II additives) is: 0.1% or 0.2% in structures with prestressing steel reinforcement; 0.2% or 0.4% in structures with ordinary steel reinforcement; 1.0% in structures without reinforcement. Such strict requirements (as well as their differentiation depending on the presence and type of reinforcement) stem from the fact that chloride ions do not only cause concrete corrosion, but also-or actually first and foremost-corrosion of steel reinforcement and other elements [7,14]. Determination of chloride content in relation to cement is convenient because it allows obtaining reproducible results and presents the proportions between the aggressive action of chlorides and the inhibiting effect of cement [37].…”